Tire/wheel assemblies are typically balanced by vehicle manufacturers prior to the installation of the tire assemblies on the vehicle. Equipment for testing the balance of tire/wheel assemblies is currently available. These testing machines generally comprise a spindle that rotates the tire/wheel assembly. The spindle is coupled to force sensors, such as load cells, which provide signals that are used to determine the location and amount of wheel weights required to correct an imbalance condition in the tire assembly. Typically, the locations where wheel weights are to be installed are marked on the tire and/or wheel. The marked wheel is then conveyed to a weight applying station where the corrective wheel weights are installed.
Balancing machines and systems are currently available that determine an imbalance condition on a tire/wheel assembly and mark a location or locations where corrective wheel weights need to be installed. Examples of the type of machines currently available can be found in U.S. Pat. Nos. 4,191,055 and 4,262,536, both of which are hereby incorporated by reference. For at least some types of currently available machines, the tire/wheel assembly size that can be tested is limited. In other types of machines, considerable downtime is encountered when the machine needs to be adjusted for a different size tire/wheel. Still other machines have unacceptably long cycle times and, as a result, have a low throughput. Today vehicle manufacturers that use this type of equipment require balancing machines that have high throughput and require minimal set-up time. Manufacturers also demand machines that can accommodate a wide range of tire/wheel sizes, operate with high reliability and have low maintenance costs.